1. Field of the Invention
This invention relates to soap wrappers and, in particular, to a bar of soap wrapped by at least a stiffening member and to a package comprising the bar of soap, the stiffening member and a wrapper entirely surrounding both the bar of soap and the stiffening member.
2. The Related Art
In the past a considerable effort has been placed into developing special fungicide containing papers and stiffener board for wrapping soap. As cellulose, which is the major constituent of paper, is an excellent growth medium for mould particularly under moist warm conditions, the use of a fungicide (often known in the USA as an xe2x80x9cantimicoticxe2x80x9d) is essential in soap packaging to prevent spoilage. These compounds serve as xe2x80x9cfungistatsxe2x80x9d; they prevent the onset of mould growth.
Unfortunately the number of fungicides that can be safely used for soap wrapping are limited, at least because some are very toxic to man. In addition, moulds can become resistant to fungicides after prolonged exposure, which necessitates changing the fungicide about every 7 years. Carbendazim and Thiabendazole have been used in the past, but are now ineffective under tropical conditions, and a significant amount of development resource has been necessary by the paper makers in developing a suitable second generation fungicide. This has required a long programme of tests and screening, which, after moulds have become resistant again, would need to be repeated if this procedure for avoiding mould growth continues to be adopted.
It is known to use a film of plastics material to wrap soap. In particular, in a known package of a bar of soap, the soap is wrapped by a conventional paper stiffener, and the soap and stiffener wrapped entirely by a film wrapper which is typically a laminated film comprising two layers each of an oriented polypropylene. The concern is however that this approach only addresses the appearance of the bar, which is enhanced by the high gloss of plastics films. It makes no difference to the problem of mould attack, as the continued use of a conventional stiffener board will still make the stiffener susceptible to attack.
Mould attack is accelerated by warm moist conditions, and as a soap bar contains free water when first wrapped, the wrapper and stiffener are initially very wet. With paper wrappers this equilibrates relatively quickly as water is lost rapidly through the paper and the folded-over, glued ends of the wrapper.
We find that if a bar of soap has, wrapped around at least a longitudinal extent thereof, a stiffening member, at least respective outer surfaces of which are each provided by a plastics material, then mould growth on and within it can be entirely avoided.
Also a normal board stiffener when it becomes wet from moisture will significantly loose strength. The ability to protect the soap during transit will therefore be reduced. However it the stiffener comprises of an inner board and two outer surfaces of a plastic material, moisture uptake by the board will be reduced, and subsequent loss in stiffness will be reduced.
Similarly, if, additionally, a wrapper, wrapped around each of the bar of soap and stiffening member, comprises a film material having at least respective outer surfaces thereof each provided by a plastics material, mould growth on and within it can be entirely eliminated.
Moreover, as shown with reference to the attached graph 1, since only the folded ends of the wrapper provide a route for moisture escape the rate of water loss is considerably decreased to provide a desired amount of water within the bar. On the other hand the film wrapper of plastics material gives a very effective moisture barrier.
In particular, in microbiological laboratory tests using moulds which are shown to be resistant to Carbendazim both films of plastics material and boards coated with plastics material have been tested for mould attack, and both were found to be completely resistant.
Indeed, we found that, even with a xe2x80x9cdouble boardxe2x80x9d stiffener coated with plastics material, fungus did not encroach through the edges.
Thus, according to one aspect, the present invention provides a bar of scap having, wrapped, laterally of the bar, around at least a longitudinal extent of the bar, a stiffening member comprising a stiff sheet material having at least respective outer surfaces thereof each provided by a plastics material, wherein at least part of the stiffening material is transparent.
The provision of a stiffening member, at least a portion of which is transparent, allows the soap to be viewed through the stiffener. Heretofore, the use of conventional paper loaded stiffeners has prevented the provision of see-through stiffeners. Further, the provision of plastic stiffeners provides improved resistance to mould attack.
Preferably, for normal soap bar sizes above 50 g the stiffness of the stiffening member is at least 3 Taber Stiffness Units in each of the longitudinal (machine) and transverse (cross) directions, and more preferably at least 8 Taber Stiffness units.
The stiffening member preferably has a grammage (weight per unit area) of 100 to 200 g/m2, and preferably has a thickness of 50 to 250 xcexcm, more preferably 160 to 180 xcexcm.
In one embodiment of the invention the entire stiffener member comprises a transparent material, as may the entire wrapper.
According to another aspect, the invention provides a package comprising a bar of soap and packaging material, which packaging material comprises a stiffening member wrapped, laterally of the bar, around at least a longitudinal extent of the bar, which stiffening member comprises a stiff sheet material having at least respective outer surfaces thereof each provided by a plastics material and including at least a transparent part; and a wrapper, wrapped around, in a manner such as entirely to surround, each of the bar of soap and stiffening member, which wrapper comprises a film material having at least a transparent part. Ideally, at least respective outer surfaces thereof are each provided by a plastics material.
At least each outer surface of the stiffening member is preferably provided by a thermoplastics material. For example, the sheet material of the stiffening member may be a laminate having a core layer of a paper board and respective outer layers each comprising a layer of thermoplastics material, preferably each having a respective thickness, independently of one another, of from 5 to 35 xcexcm. However, more preferably, the entire sheet is of a thermoplastics material, which may contain from 5 to 30%, preferably 10 to 25%, more preferably about 20%, by weight of the total weight of the stiffening member of a filler or blowing agent, or total of filler and blowing agent. Typically, the filler is an inert inorganic filler such as talc or clay. Such fillers provide improved stiffness.